What is the need for a primer strand in DNA replication?
A) it ensures the fidelity of the newly synthesized DNA strand
B) the DNA polymerases require a preexisting strand with a nucleotide having a 3' − OH
C) the DNA polymerases require a preexisting strand with a nucleotide having a 5' − OH
D) it ensures the integrity of the new DNA

Question

Quizplus · Accepted Answer

DNA polymerases can only add nucleotides to an existing 3' − OH group, which is provided by the primer. This is why primers are necessary for DNA replication to initiate.

What Is the Need for a Primer Strand in DNA